Yaeyama Islands Research Articles

Research on traditional dyed and woven fabrics of the Yaeyama Islands to utilise as a tourism resource

Katachiki (recently named Bingata) is a traditional dyed craft found in Okinawa, Japan. It involves a stencilled resist dyeing technique and dates back to the 14th and 15th centuries. Sadly, many Bingata fabrics were lost during World War II. Preserving Bingata and other traditional fabrics is important for the local community and their traditions. These fabrics also hold important benefits for tourism and sustainability, including as new textile materials, souvenirs and for their innovative designs. Professor Mitsukuni Matayoshi, Department of Industry and Information Science, College of Industry and Information Science, Okinawa International University, Japan, is working with Associate Professor Tae Hisada, Faculty of the Arts (Correspondence Education) Department of Fine and Applied Arts, and Associate Professor Kunika Sakumoto, Okinawa Christian Junior College, to research traditional dyed textiles of the Yaeyama Islands in Okinawa that can be utilised as a tourism resource. One textile that the researchers are particularly interested in is a vegetable string called Tonbyan. The researchers are working to obtain Tonbyan fibres using a new approach. Once the fibres have been acquired they will weave cloth. They hope that their method for acquiring Tonbyan fibers will be useful for craftspeople.

Observed Near-Surface Wind Structure in the Inner Core of Typhoon Goni (2015)

AbstractThe very strong Typhoon Goni passed over the Yaeyama Islands in southwestern Japan during the rapid intensification stage on August 23, 2015. Surface data collected by the dense network of weather stations as well as Doppler radar observations over the islands revealed a finescale structure in the inner core of the typhoon near the surface.Goni had a clear eye surrounded by a square-shaped eyewall with intense convection. The surface observations revealed that several vortices with a diameter of ~7–10 km accompanied by a pressure deficit were present inside the eye. From the Doppler velocity field, mesovortices approximately 10 km in diameter were found at the apexes of the square-shaped eyewall. These mesovortices and the inner rainbands emanating outward from the apexes of the polygonal eyewall generally exhibited features typical of vortex Rossby waves. The mesovortices were accompanied by a pressure deficit at the surface and enhanced surface winds. The data also indicated the first observational evidence of near-surface mixing between the eye and eyewall through the mesovortices, that is, the transport of high equivalent potential temperature in the eye toward the eyewall.The radar data revealed that many radar-reflectivity filaments that had a pleated shape with lengths of a few kilometers extended perpendicularly from the inner edge of the eyewall at low levels. The filaments associated with wind perturbations at low levels caused significant wind gusts accompanied by sudden pressure drops and shifts in wind direction at the surface.

Overexpression and purification of a toxic peptide LaIT2 from Japanese scorpion, Liocheles australasiae

In Japan, there are two species of scorpions, Madara scorpion (Isometrus maculatus) and Yaeyama scorpion (Liocheles australasiae), and both of them are living in Yaeyama island. It has been shown that Liocheles australasiae has venom including β-toxin acting on K+-channels (β-KTx) (Juichi et al., 2018) [1]. Interestingly, LaIT2, one of the toxins found in the venom of Liocheles australasiae, displays the virulence for insects but almost not for mammals. Until now, molecular mechanism of the functional specificity of LaIT2 is unknown. To clear this issue, we tried to establish the overexpression system of LaIT2 in Rosetta-gami B (DE3) pLysS, which have trxB/gor mutations to induce the disulfide bond formation. In this study, we have succeeded to overexpress the recombinant LaIT2 (rLaIT2) as a thioredoxin (Trx)-tagged protein, and established the purification protocol with Ni2+-NTA column chromatography, enterokinase digestion, and HPLC. We succeeded to obtain approximately 0.5 mg of rLaIT2 from the E. coli cells cultured in 1 L of M9 culture medium. Intramolecular disulfide bonding pattern of rLaIT2 was identified by endopeptidase fragmentation and mass spectrometry. rLaIT2 showed insecticidal activity and antimicrobial activity, and these are almost identical to those of natural LaIT2. 1H–15N HSQC spectrum of 15N-labeled rLaIT2 indicated that the rLaIT2 has a stable conformation.

Age, growth, and reproductive traits of two large emperor fishes, Lethrinus olivaceus and L. xanthochilus, around Yaeyama Islands, Okinawa, southern Japan

Age, growth, and reproductive traits of two large emperor fishes Lethrinus olivaceus (n = 144, 26.9–76.8 cm fork length) and L. xanthochilus (n = 127, 24.2–64.8 cm) were investigated in the Yaeyama Islands (24°N, 124°E), Okinawa, southern Japan. Spawning was confirmed from April to June for L. olivaceus and April to May for L. xanthochilus. Otolith opaque zones in both species were found to be formed during spawning season and to be annual marks. Maximum observed ages were 22 years old for L. olivaceus and 17 years old for L. xanthochilus. Estimated von Bertalanffy growth parameters were L∞ = 71.9 cm, k = 0.258 year− 1, t0 = − 0.613 years for L. olivaceus and L∞ = 62.5 cm, k = 0.175 year− 1, t0 = − 2.157 years for L. xanthochilus. Hermaphrodite gonads were observed in adult size of L. olivaceus and immature size of L. xanthochilus. However, dominance of females in young age classes (L. olivaceus: 1–8 years old; L. xanthochilus: 1–4 years) and of males in older age classes (L. olivaceus: >9 years old; L. xanthochilus: >5 years) implied that both species are basically functional protogynous hermaphrodite. Relatively long lives and functional protogyny, which leads to low abundance of males, indicate that both species are vulnerable to fishing pressure.

Fine-Scale Genetic Structure and Demographic History in the Miyako Islands of the Ryukyu Archipelago

The Ryukyu Archipelago is located in the southwest of the Japanese islands and is composed of dozens of islands, grouped into the Miyako Islands, Yaeyama Islands, and Okinawa Islands. Based on the results of principal component analysis on genome-wide single-nucleotide polymorphisms, genetic differentiation was observed among the island groups of the Ryukyu Archipelago. However, a detailed population structure analysis of the Ryukyu Archipelago has not yet been completed. We obtained genomic DNA samples from 1,240 individuals living in the Miyako Islands, and we genotyped 665,326 single-nucleotide polymorphisms to infer population history within the Miyako Islands, including Miyakojima, Irabu, and Ikema islands. The haplotype-based analysis showed that populations in the Miyako Islands were divided into three subpopulations located on Miyakojima northeast, Miyakojima southwest, and Irabu/Ikema. The results of haplotype sharing and the D statistics analyses showed that the Irabu/Ikema subpopulation received gene flows different from those of the Miyakojima subpopulations, which may be related with the historically attested immigration during the Gusuku period (900 − 500 BP). A coalescent-based demographic inference suggests that the Irabu/Ikema population firstly split away from the ancestral Ryukyu population about 41 generations ago, followed by a split of the Miyako southwest population from the ancestral Ryukyu population (about 16 generations ago), and the differentiation of the ancestral Ryukyu population into two populations (Miyako northeast and Okinawajima populations) about seven generations ago. Such genetic information is useful for explaining the population history of modern Miyako people and must be taken into account when performing disease association studies.

西表島で撮影された水中写真に基づくEgglestonichthys rubidus（ハゼ科）の北半球からの初記録，およびEgglestonichthysの新標準和名ライテイハゼ属

西表島で撮影された水中写真に基づくEgglestonichthys rubidus（ハゼ科）の北半球からの初記録，およびEgglestonichthysの新標準和名ライテイハゼ属

Millennial paleotsunami history at Minna Island, southern Ryukyu Islands, Japan

Huge tsunami waves have repeatedly bombarded the southern end of the Ryukyu Islands (Miyako and Yaeyama Islands, southwestern Japan) at several-hundred-year intervals. Therefore, clarifying the islands’ paleotsunami history is important for risk assessment. Nevertheless, discrepancies of paleotsunami histories exist among regional studies of tsunami boulders and sandy tsunami deposits. Radiocarbon ages of tsunami boulders indicate that tsunami events of the last 2400 years have occurred every 150–400 years, most recently the historical 1771 Meiwa tsunami. Sandy tsunami deposits at Yaeyama Islands show that four tsunami events of the last 2000 years struck the islands at approximately 600-year intervals. Sandy tsunami deposits of the Miyako Islands have been studied only rarely. Therefore, studying sandy tsunami deposits in the Miyako Islands is crucially important for clarifying the paleotsunami history of this region. We conducted a trench survey on Minna Island, located among the westernmost Miyako Islands, which revealed two sandy tsunami deposits under a coral tsunami boulder transported by the 1771 tsunami. The upper tsunami deposit was likely deposited by the 1771 tsunami, as inferred from stratigraphic correlation to the tsunami boulder. However, the lower tsunami deposit was probably deposited 700–1000 years ago, which is consistent with the age range of the paleotsunami reported for Yaeyama Islands. Because sandy tsunami deposits found in this and earlier studies are thick and deposited at high elevation and far inland, these are useful markers of large tsunami events similar to the 1771 event. However, the reported tsunami boulders of various sizes are deposited along the coast and reefs: they can be formed not only by large tsunami events but also by small ones. It is noteworthy that each tsunami deposit is coarse and thick (40–48 cm) relative to the island elevation (about 12 m maximum, 7 m above the mean sea level at the study site). By assuming that tsunamis have affected this region repeatedly during the past few thousand years at around 600-year intervals, tsunamis might have been important geomorphic agents for building up small reef-surrounded islands such as Minna Island.

教育研究における東アジアのポジショナリティ : 多層的に歴史を描く試み：沖縄県八重山諸島を事例として（コロキウム3）

教育研究における東アジアのポジショナリティ : 多層的に歴史を描く試み：沖縄県八重山諸島を事例として（コロキウム3）

Himaloconnus Franz and Nogunius gen. n. of Japan (Coleoptera: Staphylinidae: Scydmaeninae).

Two genera of Euconnus-like Stenichnini are reported to occur in Japan: Himaloconnus Franz, 1979 and Nogunius gen. n. Specimens of Himaloconnus collected on islands of the Ryukyu archipelago are identified as H. klapperichianus (Franz), previously known to inhabit Taiwan, but morphological differences were found among disjunctive populations and in consequence three new subspecies are proposed: H. klapperichianus yaeyamanus ssp. n. (Yaeyama Islands), H. klapperichianus amamianus ssp. n. (Amami-Ôshima), and H. klapperichianus okinawanus ssp. n. (Okinawa Island). Morphological structures of Japanese Himaloconnus are illustrated in detail and the diagnosis of this genus is emended, to exclude variable characters. Nogunius gen. n. is established to accommodate four species known only from Japan: N. sokani sp. n. (Okinawa Island), N. aogashimanus sp. n. (Aogashima, Izu Islands), N. kerri sp. n. (Ishigaki Island), and N. fukuuzanus sp. n. (Okinawa Island). Identification key to Japanese genera of Stenichnini is updated.

Reef influence quantification in light of the 1771 Meiwa tsunami

While interactions between regular wave driven flooding and reefs have been widely studied due to climate change pressure, the effects of reefs on tsunami flooding have less been investigated. From studies of historical events, reefs can behave as buffers or as amplifiers of inundation, depending upon the location. Interactions between reefs and tsunamis have generally been analyzed with idealized models, and there have been only few studies of specific reefs and their characteristics. Using numerical NonLinear Shallow Water models, this study characterizes the influence of the Southeast Ishigaki Island reef during the 1771 tsunami that hit the Yaeyama Islands. In this work, we modified reef topography in silico and then, measured the impact of these changes using a new parameter, the Reef Impact Factor (RIF). First, a reference model was built, simulating the real event with an accurate reef representation and using run-up data to calibrate bottom friction. This calibration highlights the difficulty of representing reef friction with a homogeneous coefficient. Second, a model without a reef was compared to the reference model. The impact of reef removal varies considerably along the coastline and maximum wave heights at the shore were strongly affected, with a 12.5% increase on average. Overall, this suggests a protective role of the reef along most of the coast. However, at local scale, channels that break the continuity of the front reef, increased wave heights by up to 40% on the proximate coast, revealing their strong focusing influence. Finally, changes in tide level, which regulates reef depth, were investigated, showing a global positive correlation between sea level and maximum wave height at the coast. However, the impact of the reef depth appeared weak compared to the impact of incident wave parameters. This study contributes to a global effort to understand tsunami-reef interactions in a non-idealized framework, suggesting a Reef Impact Factor for inter-reef/study comparisons. Moreover, vulnerable and exposed coasts were identified at Ishigaki Island, which may help to improve inundation forecasting, resulting in more appropriate management of these vulnerable sections of the coast.

Genetic Structure in Japanese and Thai Populations of the Japanese Sparrowhawk Accipiter gularis.

The Japanese sparrowhawk Accipiter gularis is a small raptor that breeds in Northeast Asia. The species consists of the widespread and mostly migratory subspecies A. g. gularis that is common in East Asia, including Japan, and the resident and endangered subspecies A. g. iwasakii which inhabits the Ryukyu and Yaeyama Islands in Okinawa, southern Japan. Given the minimal knowledge about the migration of the species, in this study we sought to compare the genetic variation of the populations breeding in Japan with those migrating through Southeast Asia. We sequenced 761 bp of mitochondrial DNA Control Region from each of 21 A. gularis collected during the breeding season in Japan and from 20 individuals intercepted on migration in Thailand. We detected 26 haplotypes among the 41 individuals which differed significantly between Japan and Thailand. Migrants in Thailand were presumed to have originated from a wide area in Eastern Eurasia. The phylogenetic and network analyses demonstrated that the haplotypes of all A. g. gularis detected in Japan were genetically close. Moreover, the Okinawa haplotypes of A. g. iwasakii were clustered with moderate genetic variation. The information presented here can be used towards implementing future conservation actions.

Correlation between Organelle Genetic Variation and RNA Editing in Dinoflagellates Associated with the Coral Acropora digitifera.

In order to develop successful strategies for coral reef preservation, it is critical that the biology of both host corals and symbiotic algae are investigated. In the Ryukyu Archipelago, which encompasses many islands spread over ∼500 km of the Pacific Ocean, four major populations of the coral Acropora digitifera have been studied using whole-genome shotgun (WGS) sequence analysis (Shinzato C, Mungpakdee S, Arakaki N, Satoh N. 2015. Genome-wide single-nucleotide polymorphism (SNP) analysis explains coral diversity and recovery in the Ryukyu Archipelago. Sci Rep. 5:18211.). In contrast, the diversity of the symbiotic dinoflagellates associated with these A. digitifera populations is unknown. It is therefore unclear if these two core components of the coral holobiont share a common evolutionary history. This issue can be addressed for the symbiotic algal populations by studying the organelle genomes of their mitochondria and plastids. Here, we analyzed WGS data from ∼150 adult A. digitifera, and by mapping reads to the available reference genome sequences, we extracted 2,250 sequences representing 15 organelle genes of Symbiodiniaceae. Molecular phylogenetic analyses of these mitochondrial and plastid gene sets revealed that A. digitifera from the southern Yaeyama islands harbor a different Symbiodiniaceae population than the islands of Okinawa and Kerama in the north, indicating that the distribution of symbiont populations partially matches that of the four host populations. Interestingly, we found that numerous SNPs correspond to known RNA-edited sites in 14 of the Symbiodiniaceae organelle genes, with mitochondrial genes showing a stronger correspondence than plastid genes. These results suggest a possible correlation between RNA editing and SNPs in the two organelle genomes of symbiotic dinoflagellates.

Studies on the genus Chrysodema (Coleoptera: Buprestidae: Chrysochroinae)part I.

Subgeneric classification of Chrysodema Laporte de Castelnau Gory, 1835 is revised and following synonymy is established: Chrysodema=Cyalithoides Fisher, 1922 syn. nov.; Pseudochrysodema Saunders, 1874=Leganya Hołyński, 1994 syn. nov.,=Marcsikiella Hołyński, 2014 syn. nov. Four subgenera are recognized as valid: Chrysodema s. str., Gelaeus Waterhouse, 1905, Pseudochrysodema Saunders, 1874, and Thymedes Waterhouse, 1905, and a key to the subgenera is given. Four species-groups are established in the subgenus Chrysodema s. str.: C. aeneoviolacea-group, C. aurostriata-group, C. eximia-group, and C. sonnerati-group. All known species, except the currently accepted synonyms of Chrysodema (Chrysodema) eximia Laporte de Castelnau Gory, 1835, included in these groups are revised based on comparative study of extensive material including types of all described taxa. Three new species and one subspecies are described: Chrysodema (Chrysodema) dany sp. nov. from Haruku Island, Indonesia; C. (C.) gottwaldi sp. nov. from Palawan Island, Philippines; C. (C.) lewisii nakatai subsp. nov. from Yaeyama Islands, Japan; and C. (C.) vrabeci sp. nov. from Thailand and Laos. Chrysodema (C.) aeneoviolacea Deyrolle, 1864 stat. rev., C. (C.) dohrnii Saunders, 1874 stat. rev., and C. (C.) fuscitarsis Kerremans, 1895 stat. rev. are removed from synonymy with C. (C.) mniszechii Deyrolle, 1864; C. (C.) tonkinea Kerremans, 1909 stat. rev. is removed from synonymy with C. (C.) aurostriata Saunders, 1866. Three new synonymies are established: C. (C.) aeneoviolacea=C. (C.) elongata Kerremans, 1900 syn. nov.=C. (C.) keyensis Théry, 1923 syn. nov. (the latter was formerly synonym of C. (C.) elongata); C. (C.) dohrnii=C. (C.) fairmairei Kerremans, 1895 syn. nov. (formerly synonym of C. (C.) mniszechii). Neotype is designated for C. (C.) sonnerati Laporte de Castelnau Gory, 1835 and lectotypes are designated for following taxa to ensure their correct application and recognition in future: C. (C.) aurostriata, C. (C.) fairmairei, C. (C.) fuscitarsis, C. (C.) sumatrensis Kerremans, 1895, C. (C.) tonkinea, C. (C.) yerburyi Waterhouse, 1905, C. (P.) coelestina Obenberger, 1922, and C. (P.) inslabilis Deyrolle, 1864. Additionally, dark species of the subgenus Pseudochrysodema are revised and as a result C. (P.) coelestina stat. rev. and C. (P.) instabilis stat. rev. are removed from synonymy with C. (P.) radians (Guérin-Méneville, 1830) and a new species C. (Pseudochrysodema) jakli sp. nov. is described from Timor Island, Indonesia. All herein included taxa are illustrated with colour photographs of habitus and the male aedeagus when available. All new taxa are diagnosed and a key to species of the C. aeneoviolacea-group is given.

Prey-tracking behavior and prey preferences in a tree-climbing firefly.

Prey-tracking behavior is common in snail-killing predators, but in the family Lampyridae, this behavior has been validated in only a single species even though this Coleopteran family includes many specialist snail predators. The endemic firefly Pyrocoelia atripennis is a major snail-killing predator in the Yaeyama Islands of Japan, and the larvae often climb on the trees and grasses at night. This tree-climbing behavior is relevant to larval food choices and anti-predatory defenses of land snails. This study examined whether lampyrid larvae can track snail mucus trails and examined larval prey preferences using alternative choice experiments. In addition, predation trials were conducted to evaluate which snail species are potential prey. P. atripennis larvae significantly selected mucous trails over distilled water or control (no-trail) treatments. In addition, a semi-arboreal species was preferred over a ground-dwelling species. In predation trials, the larvae preyed on five out of 10 endemic snail species, all of which were semi-arboreal or arboreal species. Ground-dwelling Cyclophoridae and Aegista species have effective anti-predatory defenses consisting of an operculum or “foamy-lid” that fills the shell aperture. Whether the prey has a lid affects the predation success of lampyrid larvae, and larval tree-climbing behavior may be an adaptation used to search for semi-arboreal and arboreal land snails that lack defensive lids. Furthermore, snail mucus left on the plant stem may help the lampyrid larvae to locate their prey.

Distribution pattern of Termitomyces types symbiotic with the fungus‐growing termite Odontotermes formosanus on Okinawa Island

AbstractFungus‐growing termites (subfamily Macrotermitinae) cultivate the symbiotic basidiomycete fungus Termitomyces in their fungus comb to digest cellulosic materials and to supply nitrogen‐rich fungal diet. In Japan, the fungus‐growing termite Odontotermes formosanus is found on the Yaeyama Islands and Okinawa Island, Okinawa Prefecture. Odontotermes formosanus is thought to have been recently and artificially introduced to Okinawa Island as its distribution is discontinuous and restricted to small areas. Previous DNA analyses revealed that two types of Termitomyces, namely Termitomyces sp. Type A and Termitomyces sp. Type B, whose fruiting bodies correspond to Termitomyces microcarpus‐like pseudorhiza‐lacking small mushroom and Termitomyces intermedius, respectively, are cultivated by O. formosanus on the Yaeyama Islands. However, information about the Termitomyces types cultivated by O. formosanus on Okinawa Island is limited. To define the fungal types cultivated by O. formosanus on Okinawa Island, I developed a diagnostic polymerase chain reaction method using primer sets specific to the nuclear ribosomal DNA sequences consisting of the internal transcribed spacers (ITS1 and ITS2) and 5.8S rDNA of Termitomyces not using fungal mycelium, but using the termite gut metagenome including fungal DNA as a template. The results indicated that the same two Termitomyces types from Iriomote Island are cultivated by O. formosanus on Okinawa Island. The distribution pattern of Termitomyces types on Okinawa Island showed that Termitomyces sp. Type A is limited to the mountainous side of Sueyoshi Park, despite Termitomyces sp. Type B being widely distributed in the area in which O. formosanus is found. This finding implies that O. formosanus on Okinawa Island was recently introduced from Iriomote Island to Sueyoshi Park.

Evolutionary origin of a periodical mass-flowering plant.

The evolutionary origin of periodical mass‐flowering plants (shortly periodical plants), exhibiting periodical mass flowering and death immediately after flowering, has not been demonstrated. Within the genus Strobilanthes (Acanthaceae), which includes more than 50 periodical species, Strobilanthes flexicaulis on Okinawa Island, Japan, flowers gregariously every 6 years. We investigated the life history of S. flexicaulis in other regions and that of closely related species together with their molecular phylogeny to reveal the evolutionary origin of periodical mass flowering. S. flexicaulis on Taiwan Island was found to be a polycarpic perennial with no mass flowering and, in the Yaeyama Islands, Japan, a monocarpic perennial with no mass flowering. Molecular phylogenetic analyses indicated that a polycarpic perennial was the ancestral state in this whole group including S. flexicaulis and the closely related species. No distinctive genetic differentiation was found in S. flexicaulis among all three life histories (polycarpic perennial, monocarpic perennial, and periodical plant). These results suggest that among S. flexicaulis, the periodical mass flowering on Okinawa Island had evolved from the polycarpic perennial on Taiwan Island via the monocarpic perennial in the Yaeyama Islands. Thus, the evolution of life histories could have taken at the level of local populations within a species.

Comparison of green turtle Chelonia mydas sex ratios at two time-points over 20 years at a foraging ground in Yaeyama Islands, Ryukyu Archipelago, Japan

Comparison of green turtle Chelonia mydas sex ratios at two time-points over 20 years at a foraging ground in Yaeyama Islands, Ryukyu Archipelago, Japan

書評 塚田健一著『エイサー物語――移動する人、伝播する芸能』

書評 塚田健一著『エイサー物語――移動する人、伝播する芸能』

離島周遊観光調査への Wi-Fi パケットセンシングの試行：沖縄県八重山地域を対象として

離島周遊観光調査への Wi-Fi パケットセンシングの試行：沖縄県八重山地域を対象として

Intrepid rafting weevil larvae survive 6 days at sea

There are many talented creatures in the Animal Kingdom, from swimmers and flyers to species with extreme hearing and vision, but Wen-San Huang from the National Museum of Natural Science, Taiwan, wants to add rafting to the list of extraordinary animal achievements. He knew that flightless insects, and even some small mammals, can wash up on distant shores in just a matter of days, having clung to pieces of vegetation that are washed out to sea and carried over hundreds of kilometres by strong ocean currents. However, success is only assured if the plucky seafarers are capable of surviving immersion in dehydrating saltwater. Huang also realised that insects may undertake these perilous voyages at different life stages, either as eggs or as larvae. As flightless Pachyrhynchus weevils have dispersed over great distances and successfully colonised some Pacific islands, Huang and Hui-Ying Yeh tested the resilience of one member of the family to saltwater.‘These weevils [Pachyrhynchus jitanasaius] cannot be caught using traps, so we look for them in the field and catch them in trees with nets’, says Hui-Yun Tseng, who travelled to Green Island off the coast of Taiwan with Jung-Ya Hsu to collect three pairs of the elusive beetles. Then, Yeh painstakingly collected the beetles’ minute eggs and installed them in tiny perforations in fish poison tree (Barringtonia asiatica) leaf veins to develop, first into larvae and then into adults. Once Yeh had established the P. jitanasaius colony in the laboratory, she immersed all three beetle life stages in water – ranging from fresh to brackish (16.5‰ salinity) and full seawater (35‰ salinity) – for 3, 7 and 14 days to see how the insects faired. Sadly, none of the adults survived for more than 1.5 days – even in freshwater – with most dying within the first 24 h, making it unlikely that the adults could endure such perilous crossings. However, the larvae were hardier – 25% surviving 7 days of immersion in seawater – and many went on to develop successfully into adults. But the weevil eggs were the most robust, with more than 80% hatching, regardless of the salinity.So how well would the larvae survive when burrowed within pieces of ocean-going fruit? Having implanted one weevil larva per fish poison tree fruit, Yeh installed a wave-making machine in a tank in the lab and allowed the fruit to bob about in the simulated ocean for 6 days – the length of time that it would take for a fruit to travel from the Babuyna Islands, off the Philippines, to the Japanese Yaeyama Islands. And, in an even more audacious experiment, Huang and Yeh cast some of the larvae-laden fruit adrift in the Kuroshio current off Taiwan for 6 days to find out whether any of the insects would survive. Remarkably, two of the larvae emerged alive from the lab-bound fruit and the team was even more impressed when, after retrieving the drifting fruit from the Pacific, they discovered two more survivors, both of which went on to develop into adults.‘Our study provides the first empirical evidence that P. jitanasaius larvae can survive oceanic rafting inside fish poison tree fruit’, says Huang, who suspects that the tough waterproof fruit, packed with buoyant air pockets and nutrition, could provide the ideal mode of transport for pioneering weevil settlers.